Mechanical latching arrangement for electromechanically actuated switching matrix



United States Patent 2 Claims ABSTRACT OF THE DISCLOSURE An electromechanical actuator is spring-biased toward its advanced position with sufficient force to pull up its load. It is normally disengaged from the load. To advance the load, the actuator is magnetically retracted and an interposer is drawn into place between it and the load, whereupon the magnetic force is released and the biasing spring readvances the actuator picking up the load. To release the load, the actuator is retracted and the interposer withdrawn.

Brief summary 0 the invention This invention relates to a novel mechanical latching arrangement for electromechanical actuators, and, more particularly, but not necessarily exclusively, to a novel arrangement of this type especially adapted for use in a coordinate selection actuator system of the kind wherein two actuators pulling in different directions are operated simultaneously or in predetermined order to pick up a load.

A typical coordinate selection actuator system for selectively picking up any of plural loads arranged in a coordinate matrix is shown in Vincent Patent No. 2,950,- 350, issued Aug. 23, 1960, and entitled, Crossbar Switch. In that system, main power actuators are arrayed along one side of a matrix for pulling in a direction normal to that side. Auxiliary actuators are arranged along a second side of the matrix normal to the one side or selectively moving interposers into the paths of the pull rods driven by the main actuators. So long as none of the auxiliary actuators is advanced, the main actuators are effectively decoupled from the loads and may be advanced and retracted without affecting the loads. To pick up a load, it is necessary first to advance one of the auxiliary actuators to move the interposers carried by it into the paths of the main pull rods. When thereafter one of the main actuators is advanced, the interposer in its path constitutes an interference abutment between the pull rod and the load and thus enables the pull rod to pick up the load. The interposers are spring-mounted to the auxiliary actuators for limited movement in both coordinate directions so that they are free to move with the main pull rods and once a particular load is picked up, the auxiliary actuator may be retracted without withdrawing the interposer that is in use. The main actuators, however, are spring-biased towards their retracted positions and must be held in their advanced positions either by continued electrical energization or by a remanent flux to keep their loads picked up.

The present invention is directed to an arrangement of this general type including a mechanical latching arrangement for holding the load picked up so that the main actuator need not be kept energized during the holding period, and the difiiculties of providing for magnetic latching are avoided.

Briefly, in accordance with the invention, the main actu- 7 3,427,575 Patented Feb. 11, 1969 with sufficient force to pick up their loads, and they normally rest in their advanced positions. When it is desired to pick up a load, one of the actuators is retracted and held retracted only long enough to allow for travel of an interposer into its interference position, whereupon the main actuator is de-energized and the biasing spring advances it to pick up the load. The main actuator is energized a second time to release the load.

Detailed description A representative embodiment of the invention will now be described in conjunction with the accompanying drawing, wherein the single figure is a schematic plan view of a coordinate selection actuator arrangement according to a presently preferred embodiment of the invention.

Referring now to the drawing, the actuator system shown therein includes plural main actuator pull rods 10, 11, and 12, respectively, biased toward their advanced positions, to the right as viewed in the drawing, b the springs 14 shown, or by any other desired means, with sufficient force to pick up and hold the loads for which they are designed. The loads, which may be any devices such as contact pile-ups in electrical switches, are indicated as simple blocks 16, 17, and 18, respectively, normally retracted to their left-hand positions and movable toward the right to advance them, or pick them up.

The main pull bars 10-12 carry projecting pusher lugs 20 and 22, which do not engage the loads 16-18 even in their fully advanced positions. The loads 1618 may be moved by the pull bars 10-12 only through interposers 24, 25, 26, and 27. The interposers 24-27 are spring-mounted on auxiliary rods 28, 29, and 30 arranged normall to the main pull rods 10-12, and are normally in their retracted positions, downwardly as viewed in the drawings, where they do not interfere with the projecting lugs 20 and 22, but may be advanced upwardly as viewed in the drawing into positions where, when the main pull rods 10-12 are retracted, they lie between the pusher lugs 20 and 22 and the respective loads 16-18.

When it is desired to pick up one of the loads, say, for example, the load 18 shown as the middle load adjacent to the lower one 12 of the main actuator rods, the actuator rod 12 is first retracted by momentarily energizing its actuator 32 to bring it to its retracted position as illustrated by the position of the middle actuator rod 11. The interposers 25, 26, and 27 mounted on the auxiliary pull rod 29 are then advanced by energizing the actuator 34 to which the rod 29 is connected. The main pull rod 12 is then released by de-energi-zing its actuator 32 to allow its biasing spring 14 to advance it to pull up the load 18. The interposer then rests between the pusher lug 22 and the load 18 until the main pull rod 12 is again retracted.

It has been found that for comparable loads, similar actuators may be used as used in the actuating arrangement shown and claimed in the hereinabove identified patent, even though considerably more force is required for retracting the pull rods 10 -12 against the biasing springs 14 than was required in the previous structure simply for picking up a load. This force is generated in accordance with the present invention by applying an overvoltage, which may be several times the normal rated voltage, to the actuators 32 and 34 when it is desired to retract the pull rods, and this may be done without damage to the actuators because the energizing voltage need be applied only for a few milliseconds at a time, and it is only necessary to make the actuators large enough so that in service, taking their duty cycle into account, their average energization level does not exceed their rated capacity.

What is claimed is:

1. A coordinate selection electromechanical actuator as- 3 sembly for operating an electrical switching matrix or the like comprising:

(a) a pull rod mounted for reciprocating motion in one coordinate direction between a retracted position and an advanced position,

(b) load means adjacent to said pull rod, said load means being normally biased toward said retracted position and being movable toward said advanced position,

() biasing means for biasing said pull rod toward its advanced position with suflicient force to overcome the bias of said load means and move said load means to its advanced position,

(d) an electromechanical actuator connected to said pull rod for retracting it against the urging of said biasing means from its advanced position to its retracted position,

(e) interference means carried by said pull rod for engaging and pulling an object in said one coordinate direction toward said advanced position,

(f) an interposer device, and

(g) means mounting said interposer device for reciprocating motion across said one coordinate direction into and out of a position between said interference means and said load means when said pull rod is in its retracted position.

2. A coordinate selection electromechanical actuator assembly for operating an electrical switching matrix or the like comprising:

(a) a pull rod mounted for reciprocating motion in one coordinate direction between a retracted position and an advanced position,

(b) load means adjacent to said pull rod, said load means being normally biased toward said retracted position and being movable toward said advanced position,

(0) a spring connected to said pull rod for urging it toward said advanced position with suflicient force to overcome the bias of said load means and fully to advance said load means,

(d) an electromechanical actuator connected to said pull rod for retracting it against the force of said spring from its advanced position to its retracted position,

(e) an abutment device carried by said pull rod for engaging an object and pulling it in said one coordinate direction toward said advanced position,

(if) an interposer device, and

(g) means mounting said interposer device for reciprocating motion across said one coordinate direction into and out of a position between said abutment device and said load means When said pull rod is in its retracted position.

References Cited UNITED STATES PATENTS 1,524,312 1/1925 Rasmussen 3351 15 2,338,181 1/1944 Holden 335-11-3 2,339,472 1/1944 Frederick 3351 13 2,399,962 5/1946 Vincent 200-176 3,373,384 3/1968 Lucas 335112 BERNARD A. GILH'EANY, Primary Examiner.

HAROLD BROOME, Assistant Examiner. 

